The Environmental Protection Agency (EPA) has estimated that 5% of air pollutants originate from small internal combustion engines (ICE) used in non-automotive applications. While there have been significant advances towards developing more sustainable systems to replace large ICEs, few designs have been implemented with the capability to replace small ICEs. Replacing small ICEs presents a unique opportunity for early market penetration of fuel cell technologies.
Conventional proton exchange membrane (PEM) fuel cell systems suffer from requiring high purity hydrogen. For mobile fuel cell systems, this necessitates a costly on-board hydrogen storage tank to be incorporated into the overall system design. One method to overcome this barrier is to use an on-board reforming system fueled by some sort of hydrocarbon. Hydrocarbon reforming processes (i.e., partial oxidation, steam reforming, or auto-thermal reforming) generate effluent gas compositions that typically contain various amounts of hydrogen, carbon monoxide, carbon dioxide, nitrogen, and water. Unfortunately though, most fuel reforming processes generate significant amounts of impurities, such as CO and CO2, requiring a costly and complex upfront clean-up system that is unwieldy for a practical system.
Currently, the art lacks a compact high temperature PEM fuel cell capable of operating on lower quality reformed hydrogen generated by an on-board fuel reforming system.